C-nitroso compounds and use thereof

ABSTRACT

A C-nitroso compound having a molecular weight ranging from about 225 to about 1,000 (from about 225 to about 600 for oral administration) on a monomeric basis wherein a nitroso group is attached to a tertiary carbon, which is obtained by nitrosylation of a carbon acid having a pKa less than about 25, is useful as an NO donor. When the compound is obtained from a carbon acid with a pKa less than about 10, it provides vascular relaxing effect when used at micromolar concentrations and this activity is potentiated by glutathione to be obtained at nanomolar concentrations. When the compound is obtained from a carbon acid with a pKa ranging from about 15 to about 20, vascular relaxing effect is obtained at nanomolar concentrations without gluthatione. The compound is preferably water-soluble and preferably contains a carbon alpha to the nitrosylated carbon which is part of a ketone group. In one embodiment, the C-nitroso compound is obtained by nitrosylation of a conventional drug or such drug modified to modify the carbon acid pKa thereof. When such drug is a nonsteroidal anti-inflammatory drug, the resulting C-nitroso compound functions as a COX-1 and COX-2 inhibitor without the deleterious effects associated with COX-1 inhibition but with the advantageous effects associated with COX-1 and COX-2 inhibition. One such C-nitroso compound is a nitrosoketoibuprofen. A specific example of this kind of compound is isolated as dimeric 2-[4′-(α-nitroso)isobutyrylphenyl] propionic acid. In another case, the C-nitroso compound contains the moiety  
                 
 
     where X is S, O or NR. One embodiment is directed to COX-2 inhibitors where a tertiary carbon atom and/or an oxygen atom and/or a sulfur atom is nitrosylated.

TECHNICAL FIELD

[0001] The invention relates to C-nitroso compounds which aretherapeutically active at low concentrations as NO donors.

BACK GROUND OF THE INVENTION

[0002] NO donors are known to be useful for therapeutic utility, e.g.,to prevent restenosis following angioplasty (Groves, P., et al.,Cardiovascular Research 26, 615-619 (1992)), to inhibit platelets toprevent coagulation and thrombus formation (Groves, P., et al.,Circulation 87, 590-597 (1993)) and to treat angina (Knight, et al.,Circulation 95, 125-132 (1997)). NO donors are considered to haveadditional therapeutic utility in cancer, killing microbes and viruses,relaxing airways and intestinal smooth muscle (e.g., for treating asthmaand esophageal spasms), in promoting erectile function and in treatmentof heart failure and urinary incontinence.

[0003] NO donors are described in “Methods in Nitric Oxide Research,”edited by Feelisch, M., and Stamler, J. S., John Wiley& Sons, New York,1996 at pages 71-115. These NO donors are O-nitroso and S-nitrosocompounds, and C-nitroso compounds that are excluded from the inventionherein.

[0004] Twenty-two additional C-nitroso compounds are described in Rehse,K, et al., Arch. Pharm Pharm. Med. Chem. 331, 104-110 (1998). Thesecompounds are of low molecular weight and are not water-soluble and wereshown to be weakly active. Other C-nitroso compounds are described inRehse, K., et al., Arch. Pharm. Pharm Med. Chem. 331, 79-84 (1998);these are nitro-nitroso compounds and the specific compounds mentionedare excluded from the invention herein.

[0005] Other C-nitroso compounds which are old are3-methyl-3-nitroso-2,4-pentanedione and3-ethyl-3-nitroso-2,4-pentanedione. These compounds and their synthesisare described in Sklyar, Yu. E., et al., Khimiya GeterotsiklicheskikhSoedinenii 5, 70-73 (1969). These compounds are of low molecular weightand do not meet the definition of water solubility set forthhereinafter.

SUMMARY OF THE INVENTION

[0006] It has been discovered in a first embodiment herein that certainC-nitroso compounds of higher molecular weight than have previously beenprepared, especially those that are water-soluble, are therapeuticallyactive as NO donors at nanomolar concentrations, in some cases when usedalone and in some cases in the presence of glutathione.

[0007] The C-nitroso compounds of the first embodiment herein have anitroso group attached to a tertiary carbon. Otherwise there is anessentially irreversible tautomerization to the corresponding oximewhich is generally not active. It has been discovered herein that thenitroso group being attached to a tertiary carbon is important for goodactivity.

[0008] The C-nitroso compounds of the first embodiment herein have amolecular weight ranging from about 225 to about 1,000 on a monomericbasis. The high activity obtained for compounds of this molecular weightis considered to be surprising and means that many drugs that are nowbeing used can be converted to C-nitroso compounds providing not onlythe therapeutic effect of the starting drug but also advantages providedby nitroso group including relaxation effect and other advantages asdescribed later.

[0009] The C-nitroso compounds of the first embodiment herein areobtained by nitrosylation of a carbon acid having a pKa less than about25. C-nitroso compounds derived from carbon acids with lower acidities(higher pKa values) will not act as useful donors of NO.

[0010] Thus, the invention of the first embodiment in its broad aspectsis directed to a C-nitroso compound having a molecular weight rangingfrom about 225 to about 1,000 on a monomer basis wherein a nitroso groupis attached to a tertiary carbon, which is obtained by nitrosylation ofa carbon acid having a pKa less than about 25.

[0011] The C-nitroso compound is preferably water-soluble and preferablycontains carbon alpha to nitrosylated carbon which is part of a ketonegroup.

[0012] In one subgenus, the C-nitroso compound is obtained bynitrosylation of a carbon acid having a pKa less than 10. Compounds ofthis subgenus, when used alone, have NO donating and relaxationproviding activity when used at micromolar concentrations. However, ithas been discovered herein that this activity is potentiated byglutathione, so compounds of this subgenus, when administered with or toreact with glutathione, are therapeutically active (to provide NOdonating and relaxation effects) when used at nanomolar concentrations.Thus, an embodiment herein is directed to a method of treating a patientwith such C-nitroso compound at nanomolar (e.g., from 0.1 to 900nanomolar) concentrations, together with glutathione to provide NOdonating and relaxing effect, where the patient is one in need of NOdonating and/or relaxing effect and/or is in need of nitrosoglutathione.

[0013] In another subgenus, the C-nitroso compound is obtained bynitrosylation of a carbon acid having a pKa ranging from about 15 toabout 20. It has been found in this case that the compound istherapeutically active and provides nitrosylating activity and relaxingeffect when used at nanomolar concentrations without potentiation andthat glutathione inhibits the activity of the compound.

[0014] It has been discovered herein that C-nitroso compounds of theinvention herein can be obtained by nitrosylating the tertiary carbonatom of a conventional drug if that drug constitutes a carbon acidhaving a pKa less than 25 or can be converted to a carbon acid having apKa less than 25 and will provide a C-nitroso compound meeting theaforedescribed molecular weight limitations. The resulting C-nitrosocompounds retain the activity of the drug and additionally provide therelaxation effect associated with NO and can provide other beneficialeffect as described below.

[0015] It has been discovered herein that when the conventional drug isa nonsteroidal anti-inflammatory drug that is a COX-1 and a COX-2inhibitor, the resulting C-nitroso compound will function as a COX-1 andCOX-2 inhibitor without the deleterious effects associated with COX-1inhibition but with the advantages associated with COX-1 and COX-2inhibition. In particular, COX-1 mediates production of thromboxanewhich mediates platelet aggregation thereby providing a deleteriousdeletions effect; inhibition of COX-1 reverses this effect. Thisreversal is reinforced by the C-nitroso nonsteroidal anti-inflammatorydrugs herein. On the other hand, COX-1 inhibitors inhibit production ofprostaglandins which protect against ulcers; the NO associated with thenonsteroidal anti-inflammatory drugs herein protects against thisdeleterious side effect. While the COX-1 inhibiting effect that mediatesstomach attack is partly related to a deficiency of NO, there is an NObeneficial effect that may be COX-1 independent that more than negatesthe detrimental effect of inhibition of COX-1 production ofprostaglandins. Thus, the C-nitroso nonsteroidal anti-inflammatoryCOX-1/COX-2 inhibitors herein provide an advantage over selectiveinhibitors of COX-2 in also providing the advantageous effectsassociated with COX-1 inhibition and other NO beneficial effects.Furthermore, C-nitroso selective COX-2 inhibitors provide not only theadvantages of COX-2 inhibition but also some of the advantagesassociated with COX-1 inhibition. Furthermore, the NO in C-nitroso COXinhibitors potentiates the alleviating effect of COX inhibitors onurinary incontinence.

[0016] Dimeric 2-[4′-(α-ritroso)isobutyrylphenyl]propionic acid has beensynthesized herein and is obtained by C-nitrosylation of ibuprofenmodified to have a lower carbon acid pKa. It represents a C-nitrosocompound herein obtained by nitrosylation of a carbon acid having a pKaranging from about 15 to about 25 and is therapeutically active withoutglutathione when used at nanomolar concentrations.

[0017] Thus, one embodiment herein is directed to a method of treating apatient with an inflammatory or painful disorder comprisingadministering to said patient a therapeutically effective (inflammationand/or pain relieving) amount of a C-nitroso compound of the instantinvention which is obtained by nitrosylation of the tertiary carbon of aconventional nonsteroidal anti-inflammatory drug which has a carbon acidpKa ranging from about 15 to about 20 or such modified to have thiscarbon acid pKa where the C-nitroso compound preferably is dimeric2-[4′-(α-nitroso)isobutyrylphegyl]propionic acid or an aqueous solutionthereof.

[0018] It has also discovered herein that the pKa of a carbon acid of acompound may be used to target an NO group to provide nitrosylatedcompound. This is not the case in preparing other classes of NO donor,e.g., —ONO and —SNO NO donors.

[0019] In addition, there has been discovered a new class of compounds,that are C-nitroso compounds and contain the moiety

[0020] where X is S, O or NR and protonated derivatives thereof, whichare useful in promoting compound lifetime and providing modulatedbioactivity. These compounds have a molecular weight ranging, forexample, from about 100 to about 1,000 on a monomeric basis. Thesecompounds are referred to as C-nitroso compounds of the secondembodiment herein. The compounds of Rehse, K et al., Arch. Pharm. Pharm.Med. Chem. 331, 79-84 (1998) are excluded from the new class ofcompounds herein.

[0021] Shinmura, K, et al., PNAS 97, 10197-10202 (2000) shows COX-2mediates cardioprotective effects of ischemic preconditioning, inparticular the late phase of ischemic preconditioning (in this case theheart is made ischemic briefly to protect against a subsequent ischemiathat is much more severe). Thus COX-2 inhibitors interfere with thiscardioprotective effect. However, in the case of C-nitroso COX-2inhibitors herein the NO replaces the COX-2 mediation that is lost sothere is a special benefit. This is also a similar benefit obtained withO-nitroso and S-nitroso COX-2 inhibitors. Thus, one embodiment herein isdirected to COX-2 inhibitors where a tertiary carbon or an oxygen orsulfur is nitrosylated.

[0022] As used herein, the term “carbon acid” means compound thatcontains a CH group which disassociates to C⁻ and H⁺.

[0023] As used herein, the term “water-soluble” means dissolves in waterat least to provide a concentration of 1 micromolar.

[0024] As used herein, the term “conventional drug” means therapeuticagent without NO donor effect.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIGS. 1-10 are tracings of tension (force) versus time withconcentrations of compound also shown for particular times and showresults of Example II.

[0026]FIG. 1 is directed results with compound (129a) describedhereinafter.

[0027]FIG. 2 is directed to results with C-nitroso-methyimalonic acid.

[0028]FIG. 3 is directed to result with C-nitrosobenzene.

[0029]FIG. 4 is directed to results with C-nitrosophenol.

[0030]FIG. 5 is directed to results with the C-nitrosoketoibuprofensynthesized in Example I

[0031]FIG. 6 is similar to FIG. 5 but with indications of presence ofdimer and more denotations of concentration.

[0032]FIG. 7 is directed to results for the combination of theC-nitrosoketoibuprofen and 100 μM glutathione.

[0033]FIG. 8 similar to FIG. 5 but with another concentration denoted.

[0034]FIG. 9 is directed to results for3-methyl-3-nitroso-2,4-pentanedione, including potentiation withglutathione (GSH).

[0035]FIG. 10 is directed to results for 2-methyl-2-nitrosopropane.

[0036]FIGS. 2, 3, 4, 9 and 10 are directed to results with referencecompounds although FIG. 9 is relied on for showing the potentiationeffect that occurs in one embodiment of the invention. FIGS. 1 and 5-8are directed to results with C-nitroso compound of embodiments of theinvention.

DETAILED DESCRIPTION

[0037] We turn now to the embodiment of the invention directed to aC-nitroso compound having a molecular weight ranging from about 225 toabout 1,000 on a monomer basis wherein a nitroso group is attached to atertiary carbon which is obtained by nitrosylation of a carbon acidhaving a pKa less than about 25. The molecular weight typically rangesfrom about 225 to about 600 on a monomer basis for oral administration.

[0038] We turn now to the subgenus where the C-nitroso compound isobtained by nitrosylation of a carbon acid having a pKa less than about10. When used alone, this compound displays activity (NO donating and/orrelaxation activity) when used at micromolar concentrations and willnitrosylate the modestly nucleophilic thiol of a cysteine residue or alow molecular weight derivative (e.g., glutathione). The native activityis presumably mediated by nitrite derived from nitrosylation of water.This mode of action shows little if any specificity and is very weak. Asindicated above, it has been discovered in the course of this inventionthat this activity is potentiated by the presence of glutathione. Thispotentiation is roughly 1,000-fold.

[0039] We turn now to the subgenus where the C-nitroso compound isobtained by nitrosylation of a carbon acid having a pKa ranging fromabout 15 to about 20. These C-nitrosothiols will not nitrosylateglutathione but will selectively nitrosylate highly nucleophilic thiolsfound in protein targets. Thus, highly nucleophilic thiols can betargeted by the use of these C-nitroso compounds.

[0040] The C-nitroso compounds described in “Methods in Nitric OxideResearch,” edited by Feelisch, M. and Stamler, J. S., John Wilen & Sons,New York (1996) are excluded from the invention herein.

[0041] The C-nitroso compounds described in Rehse, K., et al., Arch.Pharm. Pharm. Med. Chem. 331, 104-110 (1998) and Rehse, K, et al., Arch.Pharm. Pharm. Med. Chem., 331, 79-84 (1998) are excluded from theC-nitrosothiols of the invention.

[0042] Also excluded from the C-nitrosothiols of the invention are theC-nitrosodiones described in Sklyar, Yu. E., et al., KhimiyaGeterotsiklicheskikh Soedinenii 5,70-73 (1969).

[0043] The potentiation effect of glutathione on C-nitroso compoundsderived from carbon acids with pKa's less than 10 is new and is oneembodiment of the invention herein.

[0044] The C-nitrosylated compounds herein, when isolated, form dimerswhich are solid and very stable and therefore the compounds herein havelong shelf lives and are capable of being stored at ambient temperaturesin the presence of oxygen and light for months. While the dimers areinactive, they form monomers in water which are active. They can beadministered as aqueous solutions for instant activity. They also can beadministered as dimers to provide sustained release effect as the dimerdissolves in the body. Thus, the dimers herein have been discovered topromote compound lifetime and modulate compound bioactivity, and therelease rates are not directly related to the activity of thesecompounds. The dimerization and greater stability are greatly favoredfor α-acyl C-nitroso compounds; hence the preference above for C-nitrosocompounds where carbon alpha to the nitrosylated carbon is part of aketone group.

[0045] As indicated above, C-nitroso compound herein is obtained bynitrosylating a tertiary carbon atom of a conventional drug or of aconventional drug modified to modify the carbon acid pKa thereof Thecarbon acid pKa can be reduced, for example, by converting a carbonalpha to tertiary carbon to be nitrosylated to a ketone group or by theaddition of other electron withdrawing substituent (e.g., fluorine,nitro or cyanide).

[0046] When C-nitroso compound is obtained from a conventional drug, itretains the functionality of the drug and also provides NO donatingrelaxig effect. Sometimes this results in a synergistic effect. Forexample, when the C-nitroso compound is derived from a nonsteroidalanti-inflammatory drug which inhibits COX-1 as well as COX-2, the resultis a COX-1 inhibitor with the advantages but not the disadvantages ofCOX-1 inhibition by conventional NSAIDS and also a COX-2 inhibitor withthe advantages thereof and wherein certain beneficial effects (e.g.,amelioration of urinary incontinence or mediating preconditioning) maybe potentiated or newly endowed. A compound synthesized herein wasderived from ibuprofen which inhibits COX-1 as well as COX-2. In thesynthesis, the ibuprofen was first converted to ketoibuprofen to lowerthe pKa to be within 15 to 20. The nitrosylated compound, anitrosoketoibuprofen, isolated as dimeric2-[4′-(α-nitroso)isobutyrylphenyl]propionic acid, provides theadvantages of COX-1 and COX-2 inhibition without pathological effectstypically associated with COX-1 inhibition.

[0047] Below are listed conventional drugs and C-nitroso compounds ofthe first embodiment of the invention derived therefrom.

[0048] The analgesic acetylsalicylic acid has the formula

[0049] C-Nitroso compounds of the invention derived from acetylsalicylicacid include, for example:

[0050] In (1), (2) and (3), R₁, and R₂ are selected from the groupconsisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivatives ofthese, e.g., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0051] The antianginal propanalol has the formula:

[0052] C-Nitroso compounds of the invention derived from propanalolinclude, for example:

[0053] In (4), (5) and (6), R₁, R₂ and R₃ are selected from the groupconsisting of C₁-C₆ alkyl an C₆-C₂₀ aryl and substituted derivatives ofthese, e.g., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0054] The antianginal nadolol has the formula:

[0055] C-Nitroso compounds of the invention derived from nadololinclude, for example:

[0056] In (7), (8) and (9), R₁, R₂, R₃, R₄ and R₅ are selected from thegroup consisting of C₁-₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0057] The antianginal and heart failure protective carvedilol has theformula:

[0058] C-Nitroso compounds of the invention derived from carvedilolinclude, for example:

[0059] In (10), R₁ and R₂ are selected from group consisting of C₁-C₆alkyl and C₆-C₂₀ aryl and substituted derivatives thereof, e.g.,substituted with amino, hydroxyl and/or carboxy and/or which aresulfated and/or phosphorylated.

[0060] The antihypertensive prazosin has the formula:

[0061] C-Nitroso compounds of the invention derived from prazosin whichare exemplary of alpha adrenergic receptor agonists useful to treaterectile dysfunction, include, for example:

[0062] In (11), (12) and (13), R₁ and R₂ are selected from the groupconsisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivativesthereon e.g., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0063] The antihypertensive tinolol has the formula:

[0064] C-Nitroso compounds of the invention derived from tinololinclude, for example:

[0065] In compounds (14), (15), (16), (17), (18) and (19), R₁ and R₂ areselected from the group consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl andsubstituted derivatives thereof, e.g., substituted with amino, hydroxyand/or carboxy and/or which are sulfated and/or phosphorylated.

[0066] The antihypertensive metoprolol has the formula:

[0067] C-Nitroso compounds of the invention derived from metoprololinclude, for example:

[0068] In compounds (20), (21), (22) and (23), R₁ and R₂ are selectedfrom the group consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0069] The antihypertensive pindalol has the formula:

[0070] C-Nitroso compounds of the invention derived from pindalolinclude, for example:

[0071] Are (27) and (28) correct—note no N in ring?

[0072] In (24), (25), (26), (27) and (28), R₁ and R₂ are selected fromthe group consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0073] The antihypertensive labetalol has the formula:

[0074] C-Nitroso compounds of the invention derived from labetalolinclude, for example:

[0075] In (29), (30), (3 1) and (32), R₁ and R₂ are selected from thegroup consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0076] The diuretic triamterene has the formula:

[0077] C-Nitroso compounds of the invention derived from triamptereneinclude, for example:

[0078] In (33), R₁ and R₂ are selected from the group consisting ofC₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivatives thereof, e.g.,substituted with amino, hydroxyl and/or carboxy and/or which aresulfated and/or phosphorylated.

[0079] The diuretic furosemide has the formula:

[0080] C-Nitroso compounds of the invention derived from furosemide areuniquely useful in treating heart failure in combining diuretic andvasodilator functions and include, for example:

[0081] In (34), (35), (36) and (37), R₁ and R₂ are selected from thegroup consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0082] The ACE inhibitor enalapril has the formula:

[0083] C-Nitroso compounds of the invention herein derived fromenalapril have improved antianginal effect when used to lower bloodpressure and improved antiplatelet activity and include, for example:

[0084] In (38), (39), (40) and (41), R₁ and R₂ are selected from thegroup consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0085] The ACE inhibitor rampiril has the formula:

[0086] C-Nitroso compounds of the invention herein derived from rampirilinclude, for example:

[0087] In (42), (43), (44) and (45), R₁ and R₂ are selected from thegroup consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0088] The antihypercholesterolemic/antihyperlipoproteinemic lovastatinhas the formula:

[0089] C-Nitroso compounds of the invention herein derived fromlovastatin include, for example:

[0090] In (46), (47), (48) and (49), R₁ and R₂ are selected from thegroup consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0091] The antihypercholesterolemic/antihyperlipoproteinemic pravastatinhas the formula:

[0092] C-Nitroso compounds of the invention herein derived frompravastatin include, for example:

[0093] In (50), (51), (52), (53) and (54), R₁ and R₂ are selected fromthe group consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0094] The antihypercholesterolemic/antihyperlipoproteinemic gemfibrozilhas the formula:

[0095] C-Nitroso compounds of the invention herein derived fromgemfibrozil include, for example:

[0096] In (55), (56), (57), (58), (59) and (60), R₁ and R₂ are selectedfrom the group consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0097] The antihypercholesterolernic/antihyperlpoproteinemric clofibratehas the formula:

[0098] C-Nitroso compounds of the invention herein derived fromclofibrate include, for example:

[0099] In (61 and (62), R₁ and R₂ are selected from the group consistingof C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivatives thereof e.g.,substituted with amino, hydroxyl and/or carboxy and/or which aresulfated and/or phosphorylated.

[0100] The calcium channel blocker nifedipine has the formula:

[0101] C-Nitroso compounds derived from nifedipine include, for example:

[0102] In (63), (64) and (65), R₁ and R₂ are selected from the groupconsisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivativesthereof e.g., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0103] The calcium channel blocker amlodipine has the formula:

[0104] C-Nitroso compounds of the invention herein derived fromamlodipine include, for example:

[0105] In (66), (67), (68), (69) and (70), R₁ and R₂ are selected fromthe group consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0106] The calcium channel blocker diltiazem has the formula:

[0107] C-Nitroso compounds of the invention herein derived fromdiltiazem include, for example:

[0108] In (71), (72), (73), (74), (75) and (76), R₁ and R₂ are selectedfrom the group consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0109] The calcium channel blocker verapamil has the formula:

[0110] C-Nitroso compounds of the invention herein derived fromverapamil include, for example:

[0111] where R is the same as for (77)

[0112] where R is the same as in (77)

[0113] In (77), (78), (79), (80) and (81), R₁ and R₂ are selected fromthe group consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0114] The antacid cimetidine has the formula:

[0115] C-Nitroso compounds of the invention herein derived fromcimetidine include, for example:

[0116] In (82 and (83), R₁ and R₂ are selected from the group consistingof C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivatives thereof,e.g., substituted with amino, hydroxyl and/or carboxy and/or which aresulfated and/or phosphorylated.

[0117] The antacid ranitidine has the formula:

[0118] C-Nitroso compounds of the invention herein derived fromranitidine include, for example:

[0119] In (84) and (85), R₁ and R₂ are selected from the groupconsisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivativesthereof e.g., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0120] The bronchodilator albuterol has the formula:

[0121] C-Nitroso compounds of the invention herein derived fromalbuterol include, for example:

[0122] In (86), (87) and (88), R₁ and R₂ are selected from the groupconsisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivativesthereof; e.g., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0123] The bronchodilator ipratropium bromide has the formula:

[0124] C-Nitroso compounds of the invention herein derived fromipratropium bromide include, for example:

[0125] In (89), (90), (91), and (92), R₁ and R₂ are selected from thegroup consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0126] The NMDA antagonist/skeletal muscle relaxant memantine has theformula:

[0127] C-Nitroso compounds of the invention herein derived frommemantine include, for example:

[0128] where X is as in (95)

[0129] where X is as in (95)

[0130] In (93), (94), (95), (96) and (97), R₁ and R₂ are selected fromthe group consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0131] C-Nitroso derivatives of antiproliferative agents are especiallyuseful, as the NO group has antiproliferative effect and increases thatof the agent before NO derivatization.

[0132] The antiproliferative/tubulin binding agent 10-deacetylbaccatinIII has the formula:

[0133] C-Nitroso compounds of the invention herein that are derivativesof 10-deacetyl-baccatin III include, for example:

[0134] In (98) and (99), R₁ and R₂ are selected from the groupconsisting of C₁-C₂ alky and C₆C₂ aryl and substituted derivativesthereof, erg., substituted with amino, hydroxyl and/or cairboxy and/orwhich are sulfated and/or phosphorylated.

[0135] The antiproliferative/tubulin binding agent taxol has theformula:

[0136] C-Nitroso compounds of the invention herein derived from taxolinclude, for example:

[0137] In (100) and (101), R₁ and R₂ are selected from the groupconsisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivativesthereof, erg., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0138] The antitubercular PA-824 has the formula:

[0139] C-Nitroso compounds of the invention herein derived from PA-824include, for example:

[0140] In (102) and (103), R₁ and R₂ are selected from the groupconsisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivativesthereof, e.g., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0141] The CETP inhibitor JTT-705 (Okamoto et al., Nature 406, 203(2000)) has the formula:

[0142] C-Nitroso compounds of the invention herein derived from JTT-705include, for example:

[0143] In (104), (105), (106), (107) and (108), R₁ and R₂ are selectedfrom the group consisting of C₁-C₆ alkyl and C₆-C₂₀, aryl andsubstituted derivatives thereof e.g., substituted with amino, hydroxyland/or carboxy and/or which are sulfated and/or phosphorylated.

[0144] C-Nitroso compounds derived from SOD mimetics include, forexample:

[0145] where M is, for example, manganese, iron or cobalt, L is halide,n ranges from 0 to 4 depending on the valence of M, and R is as in(109).

[0146] In (109) and (110), R₁ and R₂ are selected from the groupconsisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivativesthereof e.g., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0147] The xanthine oxidase inhibitor allopurinol has the formula:

[0148] C-Nitroso compounds derived from allopurinol include, forexample:

[0149] In (111), (112), (113) and (114), R₁ and R₂ are selected from thegroup consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0150] The COX-2 inhibitor Celebrex has the formula:

[0151] C-Nitroso compounds derived from Celebrex include, for example:

[0152] In (115), (116), (117) and (118), R₁ and R₂ are selected from thegroup consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof, e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated.

[0153] The COX-2 inhibitor indomethacin has the formula:

[0154] C-Nitroso compounds derived from indomethacin include, forexample:

[0155] In (119), (120) and (12 1), R₁ and R₂ are selected from the groupconsisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivativesthereof, e.g., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0156] The COX-2 inhibitor L-745,337 has the formula:

[0157] C-Nitroso compounds derived from L-745,337 include, for example:

[0158] In (122), (123) and (124):

[0159] and R₁ and R₂ are selected from the group consisting of C₁-C₆alkyl C₆-C₂₀ aryl and substituted derivatives thereof e.g., amino,hydroxyl and/or carboxy and/or which are sulfated and/or phosphorylated.

[0160] The COX-2 inhibitor etudolac has the formula:

[0161] C-Nitroso compounds derived from etudolac include, for example:

[0162] In (125), (126), (127) and (128), R₁ and R₂ are selected from thegroup consisting of C₁-C₆ alkyl C₆-C₂₀ aryl and substituted derivativesthereof e.g., substituted with amino, hydroxyl and/or carboxy and/orwhich are sulfated and/or phosphorylated.

[0163] In all cases where R₁, R₂, R₃, R₄ or R₅ are defined above where His not one of the named groups, R₁, R₂, R₃, R₄ and R₅ can also be H,provided that the NO is attached to a tertiary carbon, ie., so thatdefining R₁ , R₂, R₃, R₄ and/or R₅ as H does not make NO attached to acarbon which is not a tertiary carbon.

[0164] The compounds (1)-(128) are meant to be exemplary and as oneskilled in the art would understand, in many cases the chain on whichthe NO is substituted can also be in a different location from the onedepicted.

[0165] In many of the exemplified compounds, the nitric oxide bearingfragment is linked through an ether or amino linkage. The ether linkagehas the advantage of stability in vivo. Alternatively, in some instancesit can be advantageous to link the NO-bearing fragment through an esterimage.

[0166] Examples of C-nitroso compounds of the invention herein whereNO-bearing fragment is liked through an ester linkage are set forthbelow:

[0167] In (129), (130), (131) and (132), R₁ and R₂ are selected from thegroup consisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substitutedderivatives thereof e.g., substituted with amino, hydroxyl and/orcarboxy and/or which are sulfated and/or phosphorylated, or can be H,provided that defining R₁ and R₂ as H does not make NO attached to acarbon which is not a tertiary carbon. The compounds (129), (130), (131)and (132) are meant to be exemplary, and knowing the above, one skilledin the art, could conceive of many other C-nitroso compounds of theinvention herein where NO-bearing fragment is linked through an esterlinkage.

[0168] An example of a Compound (129) is:

[0169] An example of a Compound (130) is:

[0170] Both the compounds (129a) and (130a) are obtained bynitrosylation of a carbon atom having a pKa less than about 10.

[0171] We turn now to the synthesis of the C-nitroso compounds of thefirst embodiment herein.

[0172] Several methods applicable to synthesizing C-nitroso compoundsare disclosed in Boyer, J. H., “Methods of Formation of the NitrosoGroup and its Reactions” in The Chemistry of the Nitro and NitrosoGroups, Part 1, Feuer, H., Editor, John Wiley & Sons, New York (1969) atpages 215-299 and in Touster, O. in Organic Reactions, Vol. 7, JohnWiley & Sons, New York (1955) at pages 327-377 which are incorporatedherein by reference.

[0173] In a method which is applicable to nitrosylation of carbon acidswith pKa's less than about 15, the carbon acids can be directlynitrosylated with sodium nitrite and an acid such as glacial acetic acidafter the method of Sklyar, Yu. E., et al., Khimiya GeterotsiklicheskikhSoedinenii, 5, 70-73 (1969). This method is useful for preparing thesubgenus of compounds herein which are obtained by nitrosylation of acarbon acid having a pKa less than about 10.

[0174] In a method which is applicable to nitrosylating carbon acidswith pKa's between about 15 and 30, nitrosylation is carried out byformation of the enolate and trapping the enolate by a nitrosoniumequivalent. The enolate can be trapped directly or isolated as the silylenol ether or an equivalent. This method is useful for preparing thesubgenus of compounds herein obtained by nitrosylation of a carbon acidhaving a pKa ranging from about 15 to about 20. It is the method used inExample I hereinafter for preparing dimeric2-[4′-(α-nitroso)isobutyrylphenyl]propionic acid.

[0175] In a method useful for synthesizing C-nitroso compoundsregardless of the acidity, the carbon acid is converted to thecorresponding hydroxyl amine which is oxidized, for example, usingsilver carbonate on Celite.

[0176] In the case of unstable C-nitroso compounds, it can be desirableto introduce or unmask the C-nitroso fragment only in the final step ofthe synthesis, or at least as late in the synthesis as possible. In onesuch route, the synthesis of the C-nitroso drug will first incorporatean appropriate fragment and nitrosylation is carried out only aftersynthesis is complete. An example of this route is set forth below:

[0177] In the above reaction scheme, R₁ can be selected from the groupconsisting of C₁-C₆ alkyl and C₆-C₂₀ aryl and substituted derivativesthereof (as defined for R₁ and R₂ above), and X is chlorine or bromineand PPTS is pyridinium paratoluene sulfonic acid and “pyr” is pyridine.This route is especially suitable for the preparation of compoundsderived from parent carbon acids with especially low pKa values,typically less than 15 and preferably less than 10. For compoundsderived from parent carbon acids with higher pKa values, it ispreferable to carry the C-nitroso moiety masked as the bis-protectedhydroxylamine; the C-nitroso functionality is unmasked, for example,late in the synthesis, following attachment to a conventional drug, bymild oxidation with, for example, silver carbonate on Celite; an exampleof this mode of synthesis is set forth below:

[0178] In this reaction, LDA means lithium diisopropyl amide, TMSE meanstrimethylsilylethyl, R is TMSE, PG is a protecting group, and DCC isdicyclohexylcarbodiimide.

[0179] Derivatized compounds can be prepared utilizig as nitrosylatingagent a bromomethylketone derivative of either 3-nitroso-2,4-pentanedione or 4-nitroso-2,3-butadione.

[0180] Substituted 3-nitroso-2,4-pentadiones can be prepared by thefollowing reaction scheme:

[0181] In the above reaction, scheme “PG” stands for protecting groupand “pPTS” stands for pyridinlium paratoluene sulfonic acid, R₁, R₂, R₃and R₄ are the same or different and can be the same as R₁ is definedfor reaction schemes above, and X is chlorine or bromine. Thepreparation is briefly described as follows: A group is introduced bynucleophilic substitution at the most acidic position in standardfashion. Introduction of this group prevents formation of the oximefollowing nitrosylation. The precise identity of the group is chosen tocontrol the reactivity of the C-nitroso derivative. Electrophilicnitrosylation with nitrosonium is followed by reduction to thehydroxylamine and protection as the bisacyl derivative, as described in“Bis-protected hydroxylamines as reagents in organic synthesis. Areview:” in Romine, J. L., Org. Prep. Proced. Int. 28, 249-288 (1996).Differentiation of the dione by monoprotection as the ketal is followedby introduction of one, two or three groups by nucleophilic substitutionin the standard way. Deprotection of the ketal and the hydroxyl amine isfollowed by mild oxidation to the C-nitroso compound with, for example,silver (1) salts immobilized on Celite. Finally, conversion to thebromomethyl ketone with bromine and hydrobromic acid provides thederivatizing agent.

[0182] Substituted 4-nitroso-2,3-butadiones can be prepared according tothe following reaction scheme:

[0183] In the above reaction scheme, “pPTS” is pyridimium paratoluenesulfonic acid, “LDA” is lithium diisopropyl amide and “PG” meansprotecting group R₁ and R₂ can be the same or different and can be thesame as for the reaction schemes set forth above, and X is chlorine orbromine. The preparation is briefly described as follows: The dione of2,3-butadione is differentiated as the monoketal and is then substitutedby nucleophilic substitution in the standard fashion. Nitrosylationthrough the silyl enol ether, followed by protection of the C-nitrosogroup as the diacylated hydroxylamine precedes deprotection of the ketalregeneration of the C-nitroso functionality and bromination to thereactive α-bromoketone.

[0184] In the synthesis of compounds of the first embodiment herein, thecarbon acid pKa of the starting material can be adjusted down by theprovision therein of an electron withdrawing group and the carbon acidpKa can be adjusted up by the provision therein of an electron releasinggroup.

[0185] For example, an acidic center can be introduced, e.g., formationof a ketone group from the carbon adjacent the carbon to be nitrosylatedto increase the acidity and provide lower carbon acid pKa startingmaterial. This approach was used in the synthesis of dimeric2-[4′-(α-nitroso)isobutyrylphenyl]propionic acid from ibuprofen setforth in Example I below. In the synthesis of Example I, ibuprofen(carbon acid pKa of approximately 50-55) was converted to2-(4′-isobutyrylphenyl)propionic acid (carbon acid pKa of about 20) bythis approach and the latter was converted to the final product by themethod of nitrosylating carbon acids with pKa's between about 15 and 30described above. The reaction scheme used in Example I to convertibuprofen to dimeric 2-[4′-(α-nitroso)isobutyrylphenyl]propioric acid isset forth below where 1A is ibuprofen, 4A is2-(4′-isobutyrylphenyl)propionic acid and 6A is the dimeric product.

[0186] In the above reaction scheme, “TMSC1” stands forchlorotrimethylsilane.

[0187] In summary, there are fundamentally at least two different waysof making compounds herein. One of these is to modify the parent drug tointroduce of the first embodiment herein functionality (ketone or dione)that allows C-nitrosylation. It is by this method that thenitrosoketoibuprofen is made herein. The other of these is to attach apiece or fragment to the drug that allows formation of —CNO. One methodof carrying out the latter is via a bromoketone to link via ether, amineor ester. Instead of using a bromoketone, a carboxylic acid derivativecan be reacted with hydroxy group or amine group of a conventional drugto obtain an amide or ester linkage.

[0188] The Compound (129a) can be prepared by the following route ofsynthesis:

[0189] The Compound (130a) can be prepared by the following route ofsynthesis:

[0190] We turn now to utility of the C-nitroso compounds of the firstembodiment herein.

[0191] The C-nitroso compounds of the first embodiment herein haveutility as NO donors and in such function provide relaxation andplatelet inhibiting effect. Thus, C-nitroso compounds of the firstembodiment herein are useful to prevent restenosis following angioplastyin patients at risk for restenosis following angioplasty and to inhibitplatelets to prevent coagulation and to treat angina in patients at riskfor coagulation and thrombus formation. The NO donor function alsoprovides the following therapeutic effects: inhibition of microbes andtreatment of impotence, asthma, heart failure, stroke, arthritis, ARDS,cancer and any pathological proliferation of cells and any NMDA relatedinjury.

[0192] As indicated above, the C-nitroso compounds of the firstembodiment herein with high NO-donating capacity (from carbon acids withpKa's less than about 10) exhibit weak (micromolar concentration)effects, probably through nitrite and are potentiated by addedglutathione or similar low molecular weight thiols. These compoundscause formation of nitrosoglutathione and are therefore especiallyuseful to treat patients in need of nitrosoglutathione, e.g., patientswith cystic fibrosis, asthma, hypoxia and ischemic disorders.

[0193] As indicated above, the C-nitroso compounds of the firstembodiment herein with weak NO-donating capabilities (from carbon acidswith pKa's ranging from about 15 to about 20) show high activitiesthrough specific nitrosylation of strongly nucleophilic targets and aretherefore useful to nitrosylate thiols in proteins in highlynucleophilic milieus and thus are useful to treat patients in need ofnitrosylated proteins, e.g., patients with hypertension,neurodegeneration and pain crisis of sickle cell disease.

[0194] When C-nitroso compounds of the first embodiment herein arederived from nonsteroidal anti-inflammatory drugs that inhibit COX-1 aswell as COX-2, the C-nitroso compounds are useful to treat inflammatoryor painful disorders including arthritis, coronary artery disease andurinary incontinence and improve the profile of selective inhibitors ofCOX-2, e.g., in the treatment of angina. The nitrosoketoibuprofenprepared herein has these utilities.

[0195] As indicated above and will be discussed in more depth in thedescription of advantages below, the stability of the dimeric form ofisolated C-nitroso compounds of the first embodiment herein improvescompound lifetime and provides modulated bioactivity. Thischaracteristic permits their use as sustained release drugs. Suchstability also connotes utility as prodrugs. Because spontaneous releaseof NO is both controllable and small, many C-nitroso compounds will beactive only in the presence of small molecule activators, e.g.,low-molecular weight thiols acting as carriers of NO (in an appropriateredox form) from the C-nitroso compound to a biological target.

[0196] Moreover, C-nitroso compounds of the first embodiment herein canbe incorporated into polymers for coatings on medical devices. In thecase of such coatings, polymerizable C-nitroso compounds can becopolymerized with appropriate monomers to yield plastics or elastomersas desired.

[0197] The polymers into which C-nitroso compounds of the firstembodiment herein can be incorporated include all biocompatiblepolymers, including PVP and PVP-urethane copolymers; hydrogels;polylactides and polylactide-co-polyethyleneglycol; polyacrylonitriles,polyacrylonitrile/polyacrylamide/polyacrylic acid copolymers;polyurethanes, polycarbonates, polyethers and copolymers of the three;silicone polymers and copolymers; carbohydrate polymers, includingstarches and modified starches, cellulose and cellulosidic materials,chitin and chitosan, glycosamine glycans, including hyaluronic acid,chondroitin and chondroitin sulfate, wherein the polymer has beenmodified to incorporate C-nitroso moieties derived from carbon acidswith pKa values less than about 25. The C-nitroso moieties can be boundas esters or ethers to pendant hydroxyl groups, as esters to pendantcarboxylic acids or as mines or amides to pendant amino moieties. Thenitrosylated polymer itself can be prepared in a variety of ways.Nitrosylated monomers can be incorporated into a growing polymer duringeither a free radical, ionic, metathesis or living polymerization.Alternatively, a completed polymer can be derivatized followingsynthesis to incorporate the above listed residues by treating, forexample, hydroxylated or amine-containing polymers with carboxylic acidchlorides or alkyl halides, carboxylate-containing polymers with alkylhalides. Finally, a C-nitroso precursor, for example, a monomercontaining a dione or a vinyl silane can be polymerized into a growingpolymer chain by a free radical, ionic, metathesis or livingpolymerization and then nitrosylated following polymerization byexposure to a source of nitrosonium, for example acidified nitrite,titanium tetrachloride and an alkyl nitrite, respectively.

[0198] Said polymers, can have weight average molecular weights(determined by light scattering) ranging, for example, from 50,000 to500,000.

[0199] We turn now to dosages and methods of administration for theC-nitroso compounds of the first embodiment herein when they are usedfor therapeutic utility. using part of it as the C-nitroso derivative.The reason for the wide range is that many compounds are embraced by theinvention.

[0200] Routes of administration include, for example, oral, parenteralincluding intravenous, inhaled, nebulized, and topical.

[0201] When the C-nitroso compound of the first embodiment herein isderived from a conventional drug, the dosages utilized are those in usefor the conventional drug and the methods of use are those for theconventional drug but, as indicated above, only part of the drug isadministered as the C-nitroso compound with the rest being administeredas the conventional drug, if necessary.

[0202] When the C-nitroso compound is one obtained by nitrosylation of acarbon acid having a pKa less than about 10, it is preferablyadministered in a concentration ranging from 1 nanomolar to 100micromolar as an aqueous solution unless potentiation is provided byglutathione or other low-molecular weight thiol whereupon the C-nitrosocompound is preferably administered in a concentration ranging from 1 to900 nanomolar and the glutathione is administered in a concentrationranging from 1 micromolar to 100 millimolar.

[0203] When the C-nitroso compound is one that is obtained from a carbonacid having a pKa ranging from about 15 to about 20, the C-nitrosocompound is preferably administered in a concentration ranging fromabout 1 nanomolar to 100 micromolar.

[0204] We turn now to the ibuprofen derivative, i.e., dimeric2-[4′-(α-nitroso)isobutyrylphenyl]propionic acid. It is preferablyadministered as a pill, tablet or capsule or the like, with only part ofthe ibuprofen being administered as the C-nitroso derivative, e.g., onepart by weight ibuprofen derivative, to 1,000 parts by weightunderivatized ibuprofen to provide 400 mg on an ibuprofen basis, threeto four times day and from 1 nanomolar to 100 micromolar C-nitrosocompound concentration.

[0205] The compounds of the first embodiment herein are advantageousover the C-nitroso compounds known heretofore in activity and/or insolubility.

[0206] We turn now to the advantages of the C-nitroso compounds of thefirst embodiment herein over O-nitroso compounds and S-nitroso compoundsas NO donors.

[0207] A major barrier to use of organic nitrites and nitrosothiols asNO (or nitrosonium) donors is their instability. For example,nitrosothiols undergo rapid decomposition to yield inter alia nitricoxide radical and a sulfur radical. In contrast, C-nitroso compounds ofthe first embodiment undergo a dimerization reaction to produce a solid,stable dimer. As indicated above, this dimerization reaction proceedsspontaneously during isolation of C-nitroso compounds and thedimerization is greatly favored for α-acyl C-nitroso compounds. Ingeneral, the dimers are solid and stable, capable of being stored atambient temperature in the presence of oxygen and light for months. TheC-nitroso compounds herein have a significant advantage over O-nitrosoand S-nitroso compounds of the first embodiment from the standpoint ofshelf stability.

[0208] The C-nitroso compounds of the first embodiment herein are alsoadvantageous over O-nitroso and S-nitroso compounds as NO donors in thattheir functionality, i.e., NO donating potential and reactivity, can betailored, while this is not the case for O-nitroso and S-nitrosocompounds.

[0209] We turn firstly to tailoring the NO donating potential ofC-nitroso compound of the first embodiment herein. This can be done inthree ways. Firstly, the rate of transfer of nitrosonium equivalent isdirectly proportional to acidity. Thus, NO donating potential isincreased by obtaining C-nitroso compound from starting material withlower pKa. Secondly, the NO donating potential is related to theposition (equilibrium constant) of the dimer-monomer equilibrium(thermodynamics). This property is because, as indicated above, thedimer is stable and inactive whereas the monomer is active. Thirdly, theNO donating potential is influenced by the rate of interconversion ofthe dimer and monomer (kinetics). This feature can be utilized, forexample, by positioning an acyl alpha to the nitroso carbon to slow downthe rate of interconversion to monomer. On the other hand, theNO-donating capability of organic nitrites and nitrosothiols is largelya function of the heteroatom (oxygen or sulfur); there is little in theway of relationship between structure and activity.

[0210] We turn now to tailoring of the reactivity of C-nitrosocompounds. This can be accomplished sterically or electronically. Weturn now to the steric tailoring of reactivity. The addition of stericbulk at the α-carbon slows transfer of a nitrosonium equivalent. Thus,for example, highly hindered protein sulphydryl receptors can beprotected against S-nitrosylation through use of highly hinderedC-nitroso donors. We turn now to electronic tailoring of reactivity.Firstly, the rate of transfer of nitrosonium equivalent is directlyproportional to the acidity of the parent carbon acid. Secondly, thereactivity can be tailored by selecting starting material with groupsthat can tailor donating potential. For example, addition of groups suchas acyl and electronegative substituents, will lower the acidity of thecarbon acid and in turn enhance the NO⁺ donating capacity of theC-nitroso compound. Moreover, alteration of groups changes the form ofnitric oxide liberated. The alteration of groups can change the acidityas much as 10⁴⁰, greatly exceeding the range available with sulfur oroxygen-based conjugates.

[0211] Methods for providing different groups in C-nitroso compound areavailable in the methods of synthesis described above wherebromomethylketone derivatives of either 3-nitroso-2,4-pentanedione on4-nitroso-2,3-butadione are used and these groups can influence themonomer-dimer properties and NO-donating potential of the final product.

[0212] We turn now to the C-nitroso compounds of the second embodimentherein. These contain the moiety

[0213] where X is S, O or NR where R is selected from the groupconsisting of C₁-C₆ alkyl which is unsubstituted or which is substitutedwith one or more alcohol, ether; ester or amide groups which containfrom 2 to 10 carbon atoms; and has a molecular weight ranging, forexample, from about 100 to about 1,000.

[0214] A preferred subgenus of the second embodiment herein comprise thestructure:

[0215] where X is S, O or NR where R is as defined for the genus of thesecond embodiment and n ranges from 0 to 4 and the correspondingprotonated compounds (instead of existing with the negative charge).

[0216] The structure (135) may be substituted with C₁-C₆ alkyl or C₁₋₆alkyl carbonyl and includes the modification that the carbon pendant toX and a carbon within the parentheses can also be part of another ring.For example, a compound of the second embodiment herein is:

[0217] The compounds of the second embodiment form spontaneously fromcorresponding C-nitroso compounds that contain alcohol, thiol or amine.For example, the Compound (135a) is formed by the following route ofsynthesis:

[0218] where Bz stands for benzoyl.

[0219] The compounds of the second embodiment herein have utility as NOdonors as described above in conjunction with the C-nitroso compounds ofthe first embodiment and are used with the dosage ranges and routes ofadministration described in conjunction with the C-nitroso compounds ofthe first embodiment and are characterized by similar stability to thedimers of the C₁-nitroso compounds of the first embodiment.

[0220] We turn now to the embodiment herein directed to inhibitors ofCOX-2 where a tertiary carbon on an oxygen or a sulfur is nitrosylated.

[0221] Examples of inhibitors of COX-2 where a tertiary carbon isnitrosylated are compounds (115)-(128) set forth above.

[0222] Examples of inhibitors of COX-2 where an oxygen or sulfur isnitrosylated include, for example, derivatives of Celebrex,indomethacin, L-745,337, and etudolac.

[0223] Examples of compounds derived from Celebrex include thefollowing:

[0224] Examples of compounds derived from indomethacin include thefollowing:

[0225] An example of a compound derived from L-745,337 is

[0226] Examples of compounds derived from etudolac include thefollowing:

[0227] In the compounds (200), (201), (202), (203), (204), (205) and(206), Y is S or O; R₁ and R₂ are H or C₁-C₆ alkyl; and X is C₁-C₆ alkylC₆-C₂₀ aryl and substituted derivatives thereof e.g., substituted withamino, hydroxyl, and/or carboxy and/or which are sulfated and/orphosphorylated.

[0228] The COX-2 inhibitor compounds which are O-nitrosylated areobtained from the parent alcohol by treatment with an appropriatenitrosylating agent, e.g., acidified nitrite, nitrosyl chloride,nitrosyl bromide, nitrosonium perchlorate, nitrosonium hydrogen sulfateor nitrosonium tetrafluoroborate.

[0229] The COX-2 inhibitor compounds which are S-nitrosylated areobtained from the parent thiol by treatment with an appropriatenitrosating agent, e.g., those set forth in the paragraph directly aboveor alkyl nitrite.

[0230] The dosage on a COX-2 inhibitor basis is the same as the dosagefor the underivatized COX-2 inhibitor. To effect this, only part of theCOX-2 inhibitor can be administered in the form of nitrosylatedcompound. The route of administration is the same as for theunderivatized COX-2 inhibitor.

[0231] The invention is illustrated by the following working examples.

EXAMPLE I Synthesis of Dimeric2-[4′-(α-Nitroso)isobutyrylphenyl]propionic Acid

[0232] The synthesis of dimeric2-[4′-(α-nitroso)isobutyrylphenyl]propionic acid was carried outaccording to the reaction scheme for this set forth above as follows:

[0233] To a solution of ibuprofen 1A (9.89 g, 48 mmol) in anhydrous EtOH(35 mL) was added chlorotrimethylsilane (18.27 mL, 144 mmol) at roomtemperature, and the mixture was stirred at the same temperature for 2h. After the removal of the excess EtOH and chlorotrirethylsilane underreduced pressure, the oily residue was treated with ice-cold saturatedNaHCO₃ (150 mL), and the resulting mixture was extracted with hexanes(450 mL). The hexanes solution was washed with brine (3×50 mL), anddried over anhydrous Na₂SO₂. Evaporation of the solvent afforded ethyl2-(4′-isobutylphenyl)propionate 2A (11.24 g, in 100% yield) as acolorless oil.

[0234] Ester 2A (11.23 g, 48 mmol) was added dropwise to a stirredsuspension of CrO₃ (20.8 g, 208 mmol) in acetic acid (AcOH) (34 mL) andH₂O (1.1 mL) within 30 min, maintaining the reaction temperature at45-55° C. After the completion of addition, the mixture was stirred for20 mn. and then the mixture was heated with stirring at 50-55° C. foradditional 85 min, giving a blue-black suspension. The AcOH was removedunder reduced pressure, and the residue solid was suspended in ice-coldH₂O (400 mL), and extracted with EtOAc (450 mL). The extract was washedwith brine (5×50 mL), and dried (Na₂SO₄). The crude products werepurified by flash chromatography (eluting with 7% EtOAc in hexanes) togive unreacted ester 2A (2.78 g), followed by ethyl2-(4′-isobutyrylphenyl)propionate 3a (4.3 g, 48% yield based on consumed2A) as a light-yellow oil.

[0235] Fifteen percent aqueous NaOH (10 mL) was added to a solution of3A (3.2 g, 12.9 mmol) in MeOH (150 mL), and stirred at room temperaturefor 2 h. After the removal of the MeOH by evaporator, the dark-brownresidue was treated with ice-cold 2M HCl (100 mL), and the resultinggrey-white suspension was extracted with EtOAc (400 mL), and finallydried (Na₂SO₄). Flash chromatographic purification of the crude products(eluting with 60% EtOAc in hexanes) afforded2-(4′-isobutyrylphenyl)propionic acid 4a (2.5 g, 88% yield) as anamorphous solid.

[0236] To a stirred mixture of 4A (1.59 g, 7.2 mmol) and triethylamine(3.03 mL, 21.7 mmol) was added chlorotrimethylsilane (2.75 mL, 21.7mmol) at room temperature, and then a solution of sodium iodide (3.26 g,21.7 mmol) dissolved in anhydrous acetonitrile (25 mL) was introduced inone portion. The mixture was stirred at room temperature for 8 h, thenextracted with hexanes (400 mL). The hexanes extract was washed withice-cold brine (2×30 mL), and dried (Na₂SO₄). Concentration of thesolvent afforded trimethylsilyl2-[4′-(1-trimethylsiloxy-1-isobutenyl)phenyl]propionate 5A (2.08 g, 79%yield) as a viscous oil, which was used without further purification.

[0237] A solution of 5A (2.1 g, 5.7 mmol) dissolved in anhydrous CH₂Cl₂(25 mL) was cooled to −10° C. Isoamyl nitrite (2.4 mL, 17.6 mmol) wasadded in one portion, then 1M TiCl₄ CH₂Cl₂ solution (13.0 mL, 13.0 mmol)was added dropwise at −10° C. within a period of 20 min. After stirringat the same temperature for additional 60 min, the resulting deep-greenmixture was poured into ice-cold H₂O (100 mL), and stirred for 5-10 min,then extracted with EtOAc (400 mL), and finally dried (Na₂SO₄).Evaporation of the solvent under reduced pressure gave an amorphoussolid, which was suspended in CH₂Cl₂ (50 mL) and collected byfiltration. The white solid was washed with additional CH₂Cl₂ (3×10 mL)to give dimeric 2-[4′-(α-nitroso)isobutyrylphenyl]propionic acid 6A(0.75 g, 53% yield).

EXAMPLE II

[0238] The ability of various C-nitroso compounds as described below torelax a rabbit aortic ring (smooth muscle) was carried out as describedin Stamler, J., et al., PNAS, Vol. 89, 444-448 (1992).

[0239] Results shown in FIGS. 1-10 which are tracings of force (tension)in the Y-direction versus time in the X-direction with downwarddirection indicating relaxation and upward direction indicatingconstriction. Concentrations of C-nitroso compound applied at time inthe X-direction are indicated as 10⁻⁹ (1 nanomolar), 10⁻⁶ (1micromolar), 10⁻³ (1 milimolar), etc. “PE” on the figures means theapplication of phenylephrine, a constricting agent.

[0240]FIG. 1 shows results for Compound (129a) which is a C-nitrosocompound obtained by nitrosylating a carbon acid with a pH less than 10.Relaxation effect is shown in FIG. 1 at 10 μM concentration, i.e., atmicromolar concentrations.

[0241]FIG. 2 shows results for C-nitroso-methylmalonic acid. It isobtained from a carbon acid with a pKa of about 30-35. As shown in FIG.2, it displays relaxation effect at 10 micromolar concentration (veryweak activity).

[0242]FIG. 3 shows results for C-nitrosobenzene. It is obtained from acarbon acid having a pKa of about 45. As shown in FIG. 3, it displays noactivity at micromolar concentration.

[0243]FIG. 4 shows results for C-nitrosophenol. C-Nitrosophenol isobtained from a carbon acid having a pKa greater than 25. As shown inFIG. 4, it displays no activity at micromolar concentrations.

[0244]FIG. 5 shows results for the nitrosoketoibuprofen synthesized inExample I. As shown in FIG. 5, it displays relaxation effect at 10nanomolar concentration.

[0245]FIG. 6 shows further results for the nitrosoketoibuprofensynthesized in Example I. FIG. 6 shows the same relaxation effect at 10nanomolar as does FIG. 7 but not much more activity at higherconcentration (since the equilibrium moves in the direction of inactivedimer at higher concentrations).

[0246]FIG. 7 shows results for the nitrosoketoibuprofen synthesized inExample I used in conjunction with 100 μM glutathione. As shown in FIG.7, there is no activity because glutathione blocks the activity of thenitrosoketoibuprofen by complexing with it to tie up the NO group (thesame occurrence as for dimer); this is a reflection of the C—N(O)R groupdescribed above.

[0247]FIG. 8 shows more results for the nitrosoketoibuprofen synthesizedin Example I. Relaxation is shown at 1 and 10 nM concentration. Thisdiffers some from what is shown in FIGS. 5 and 6 because of the naturalvariability among blood vessels.

[0248]FIG. 9 shows results for 3-methyl-3-nitroso-2,4-petanedione whichis obtained from a carbon acid with a pKa less than 10. This compound isnot water soluble. It displays relaxation effect at concentrationgreater than 10 micromolar and further effect at concentration greaterthan 100 micromolar, but when 100 μm glutathione is added it displaysrelaxation effect at between 1 and 10 nanomolar concentration. Thepotentiation effect occurs because the C-nitrosodione reacts withglutathione to form S-nitrosoglutathione.

[0249]FIG. 10 shows results for 2-methyl-2-nitrosopropane. It isobtained from a carbon acid having a pKa of about 55 and is not watersoluble. It displays no relaxation effect activity at any of theconcentrations used.

EXAMPLE III

[0250] A 60-year-old white male with arthritis, esophageal spasm,coronary artery disease, congestive heart failure, impotence and nightlyurinary incontinence develops gastrointestinal upset when administeredibuprofen (400 mg, three times a day). When the drug is changed so that0.1% by weight of the drug is administered as the dimericnitrosoketoibuprofen of Example I, all symptoms are relieved.

EXAMPLE IV

[0251] A 65-year-old male with angina treated with nitroglycerindevelops nitrate tolerance. Nitroglycerin administration is stopped andCompound (135a) is given at 20 μg/min continuously with relief ofangina.

EXAMPLE V

[0252] A 62-year-old white male with severe rheumatoid arthritispresents with myocardial infection. His nonsteroidal anti-inflammatorydrug is stopped because of concerns of increased cardiovascular risk.His joint pain becomes debilitating. Celebrex is administered orallytwice a day in 200 mg amount except that 0.1% by weight of the drug isadministered as Compound (115) where R₁ and R₂ are methyl, with reliefof both joint pain and angina.

[0253] When Compound (200) where R₁ and R₂ are H and X is —CH₂—, and Yis S or O is substituted for the Compound (115) in equal amount, reliefof both joint pain and angina is also obtained.

[0254] Variations

[0255] Variations of the above will be obvious to those skilled in theart. Thus, the scope of the invention is defined by the claims.

What is claimed is:
 1. A C-nitroso compound having a molecular weightranging from about 225 to about 1,000 on a monomeric basis wherein anitroso group is attached to a tertiary carbon, which is obtained bynitrosylation of a carbon acid having a pKa less than about
 25. 2. TheC-nitroso compound of claim 1 which is water-soluble.
 3. The C-nitrosocompound of claim 2 where a carbon alpha to the nitrosylated carbon ispart of a ketone group.
 4. The C-nitroso compound of claim 3 which has amolecular weight ranging from about 225 to about 600 on a monomericbasis.
 5. The C-nitroso compound of claim 4 which is obtained bynitrosylation of a carbon acid having a pKa less than about
 10. 6. TheC-nitroso compound of claim 4 which is obtained by nitrosylation of acarbon acid having a pKa ranging from about 15 to about
 20. 7. TheC-nitroso compound of claim 1 in dimeric form.
 8. A C-nitroso compoundas defined in claim 1 which is obtained by nitrosylating a tertiarycarbon of a conventional drug or of a conventional drug modified tomodify the carbon acid pKa thereof.
 9. A C-nitroso compound as definedin claim 2 which is obtained by nitrosylating a tertiary carbon of aconventional drug or a conventional drug modified to modify the carbonacid pKa thereof.
 10. A nitroso compound as defined in claim 3 which isobtained by nitrosylating a tertiary carbon of a conventional drug or ofa conventional drug modified to modify the carbon acid pKa thereof. 11.A C-nitroso compound as defined in claim 4 which is obtained bynitrosylating a tertiary carbon of a conventional drug or of aconventional drug modified to modify the carbon acid pKa thereof.
 12. AC-nitroso compound as defined in claim 5 which is obtained bynitrosylating a tertiary carbon of a conventional drug or of aconventional drug modified to modify the carbon acid pKa thereof.
 13. AC-nitroso compound as defined in claim 6 which is obtained bynitrosylating a tertiary carbon of a conventional drug or of aconventional drug modified to modify the carbon acid pKa thereof.
 14. AC-nitroso compound as defined in claim 7 which is obtained bynitrosylating a tertiary carbon atom of a conventional drug or of aconventional drug modified to modify the carbon acid pKa thereof wheredimerization proceeds spontaneously during isolation of the product ofnitrosylation.
 15. A C-nitroso compound as defined in claim 13 where theconventional drug is a nonsteroidal anti-inflammatory drug.
 16. AC-nitroso compound as defined in claim 15 where the nonsteroidalanti-inflammatory drug is ibuprofen.
 17. A C-nitroso compound as definedin claim 16 which is a nitrosoketoibuprofen in dimeric form.
 18. TheC-nitroso compound of claim 17 which is dimeric2-[4′-(α-nitroso)isobutyrylphenyl]propionic acid.
 19. A method oftreating a patient with an inflammatory or pail disorder comprisingadministering to said patient a therapeutically effective amount of acompound as defined in claim 15 or an aqueous solution thereof.
 20. Amethod of treating a patient with an inflammatory or painful disordercomprising administering to said patient a therapeutically effectiveamount of a compound as defined in claim 16 or an aqueous solutionthereof.
 21. A method of treating a patient with an inflammatory orpainful disorder comprising administering to said patient atherapeutically effective amount of a compound as described in claim 17or an aqueous solution thereof.
 22. A method of treating a patient withan inflammatory or painful disorder comprising administering to saidpatient a therapeutically effective amount of a compound as defined inclaim 18 or an aqueous solution thereof.
 23. A method of treating apatient in need of nitrosoglutathione which comprises administering tosaid patient a therapeutically effective amount of a compound as claimedin claim 5 optionally with administration of glutathione.
 24. AC-nitroso compound containing the moiety

where X is S, O or NR where R is selected from the group consisting ofC₁-C₆ alkyl which is unsubstituted or which is substituted with one ormore alcohol, ether, ester or amide groups which contain from 2 to 10carbon atoms, and has a molecular weight ranging from about 100 to about1,000.
 25. C-Nitroso compounds according to claim 24 which comprises thestructure:

where X is S, O or NR and n ranges from 0 to 4 and the correspondingprotonated compounds.
 26. A COX-2 inhibitor where a tertiary carbon atomand/or a sulfur atom and/or an oxygen atom is nitrosylated.